Elucidating how epithelial cell polarity maintenance safeguards genome stability during cell division.

阐明上皮细胞极性维持如何在细胞分裂过程中保障基因组稳定性。

• 批准号: 2596652
• 金额: --
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2596652
• 关键词: Elucidating; how; epithelial; cell; polarity

Polarised epithelial cell divisions represent a critical mechanism for correct partitioning of fate determinants and genomic material into the daughter cells during tissue homeostasis and morphogenesis, and their disruption can lead to severe developmental disorders and diseases such as premature aging and cancer. Yet, the precise mechanisms coordinating cell polarity and correct mitotic spindle dynamics and chromosome segregation fidelity, to ensure proper epithelial integrity and differentiation remain ill defined. In a recent screen, we identified a novel protein complex including the membrane-associated Annexin A1 (ANXA1) protein and its partner S100A11 that interacts with the evolutionarily conserved LGN mitotic complex in mammary epithelial cells. Preliminary observations, show that disruption of ANXA1-S100A11 complex results in defective spindle dynamics and abnormal chromosome segregation, leading to cytokinesis defects and impaired cell-cell adhesion. This collaborative project will provide the PhD student with a cutting-edge multidisciplinary training in cell biology and biotechnology combined with 3D and super-resolution imaging to test the hypothesis that ANXA1-S100A11 coordinates cell polarity, spindle dynamic and faithful chromosome alignment and segregation to ensure epithelial integrity. To specifically study the role of ANXA1-S100A11 complex during mitosis, the PhD candidate will employ CRISPR/Cas9 genome editing to generate mammary epithelial cells expressing endogenously degron-tagged ANXA1 and S100A11 to induce acute protein depletion during cell division. By combining advanced and super-resolution microscopy technology, the PhD student will dissect the role(s) of ANXA1-S100A11 complex in the coordination of the dynamics of cell-cell adhesion molecules, LGN spindle orientation machinery and chromosome stability regulators (also identified in our screen) in a nanoscale. The PhD student will further extend the study in stem cell-derived mammary 3D organoids combined with 3D confocal imaging to assess the impact of ANXA1-S100A11-loss-mediated defects on epithelial integrity and differentiation during morphogenesis. This project will provide a significant mechanistic insight on how ANXA1-S100A11 (probably the first characterised protein complex) bridges cell polarity control and chromosome stability maintenance to ensure proper epithelial architecture and prevent malignant transformation. Our findings will be used for more ambitious proposals for BBSRC or MRC project grants, using mouse and mathematical models to investigate how disruption of these mechanisms in vivo can contribute to premature aging and cancer.

极化上皮细胞分裂代表了在组织稳态和形态发生期间将命运决定子和基因组物质正确分配到子细胞中的关键机制，并且它们的破坏可导致严重的发育障碍和疾病，例如过早衰老和癌症。然而，协调细胞极性和正确的有丝分裂纺锤体动力学和染色体分离保真度，以确保适当的上皮完整性和分化的精确机制仍然不清楚。在最近的筛选中，我们确定了一种新的蛋白质复合物，包括膜相关膜联蛋白A1（ANXA 1）蛋白及其伴侣S100 A11，该蛋白质复合物与乳腺上皮细胞中进化保守的LGN有丝分裂复合物相互作用。初步观察表明，ANXA 1-S100 A11复合物的破坏导致纺锤体动力学缺陷和染色体分离异常，导致胞质分裂缺陷和细胞-细胞粘附受损。该合作项目将为博士生提供细胞生物学和生物技术方面的尖端多学科培训，并结合3D和超分辨率成像，以测试ANXA 1-S100 A11协调细胞极性，纺锤体动态和忠实的染色体对齐和分离以确保上皮完整性的假设。为了专门研究ANXA 1-S100 A11复合物在有丝分裂过程中的作用，博士候选人将采用CRISPR/Cas9基因组编辑来产生表达内源性脱氮标记的ANXA 1和S100 A11的乳腺上皮细胞，以诱导细胞分裂过程中的急性蛋白质消耗。通过结合先进的超分辨率显微镜技术，博士生将剖析ANXA 1-S100 A11复合物在纳米级细胞-细胞粘附分子，LGN纺锤体取向机制和染色体稳定性调节剂（也在我们的屏幕中确定）的动力学协调中的作用。博士生将进一步扩展干细胞衍生的乳腺3D类器官的研究，结合3D共聚焦成像，以评估ANXA 1-S100 A11缺失介导的缺陷对形态发生期间上皮完整性和分化的影响。该项目将提供关于ANXA 1-S100 A11（可能是第一个表征的蛋白质复合物）如何桥接细胞极性控制和染色体稳定性维持以确保适当的上皮结构并防止恶性转化的重要机制见解。我们的研究结果将用于BBSRC或MRC项目赠款的更雄心勃勃的提案，使用小鼠和数学模型来研究这些机制在体内的破坏如何导致过早衰老和癌症。